Merge pull request #1350 from josephschorr/avoid-slice-realloc

Avoid reallocation of slice in preloaded task runner
authzed · May 24, 2023 · 140b41e · 140b41e
2 parents 2fb89c4 + 7ab3be6
commit 140b41e
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Showing 3 changed files with 6 additions and 6 deletions.
diff --git a/internal/graph/check.go b/internal/graph/check.go
@@ -791,7 +791,7 @@ func dispatchAllAsync[T any](
 	resultChan chan<- CheckResult,
 	concurrencyLimit uint16,
 ) {
-	tr := newPreloadedTaskRunner(ctx, concurrencyLimit)
+	tr := newPreloadedTaskRunner(ctx, concurrencyLimit, len(children))
 	for _, currentChild := range children {
 		currentChild := currentChild
 		tr.add(func(ctx context.Context) error {

diff --git a/internal/graph/preloadedtaskrunner.go b/internal/graph/preloadedtaskrunner.go
@@ -22,7 +22,7 @@ type preloadedTaskRunner struct {
 	tasks []TaskFunc
 }
 
-func newPreloadedTaskRunner(ctx context.Context, concurrencyLimit uint16) *preloadedTaskRunner {
+func newPreloadedTaskRunner(ctx context.Context, concurrencyLimit uint16, initialCapacity int) *preloadedTaskRunner {
 	// Ensure a concurrency level of at least 1.
 	if concurrencyLimit <= 0 {
 		concurrencyLimit = 1
@@ -33,7 +33,7 @@ func newPreloadedTaskRunner(ctx context.Context, concurrencyLimit uint16) *prelo
 		ctx:    ctxWithCancel,
 		cancel: cancel,
 		sem:    make(chan token, concurrencyLimit),
-		tasks:  make([]TaskFunc, 0),
+		tasks:  make([]TaskFunc, 0, initialCapacity),
 	}
 }
 

diff --git a/internal/graph/preloadedtaskrunner_test.go b/internal/graph/preloadedtaskrunner_test.go
@@ -17,7 +17,7 @@ import (
 func TestPreloadedTaskRunnerCompletesAllTasks(t *testing.T) {
 	defer goleak.VerifyNone(t)
 
-	tr := newPreloadedTaskRunner(context.Background(), 2)
+	tr := newPreloadedTaskRunner(context.Background(), 2, 5)
 	wg := sync.WaitGroup{}
 
 	for i := 0; i < 5; i++ {
@@ -44,7 +44,7 @@ func TestPreloadedTaskRunnerCancelsEarlyDueToError(t *testing.T) {
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	tr := newPreloadedTaskRunner(ctx, 3)
+	tr := newPreloadedTaskRunner(ctx, 3, 10)
 	completed := sync.Map{}
 
 	for i := 0; i < 10; i++ {
@@ -82,7 +82,7 @@ func TestPreloadedTaskRunnerCancelsEarlyDueToCancel(t *testing.T) {
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	tr := newPreloadedTaskRunner(ctx, 3)
+	tr := newPreloadedTaskRunner(ctx, 3, 10)
 	completed := sync.Map{}
 
 	for i := 0; i < 10; i++ {